Photochlor (HTTP), a photodynamic therapy (PDT) agent, is a lipophilic, second-generation, chlorin-based photosensitizer. Upon IV administration, HPPH selectively accumulates in the cytoplasm of cancer or pre-cancerous cells. When laser light is applied, a photodynamic reaction between HPPH and oxygen occurs, resulting in the production of cytotoxic free radicals and singlet oxygen and free radical-mediated cell death. Compared to the first-generation photosensitizer porfimer sodium, HPPH shows improved pharmacokinetic properties and causes only mild skin photosensitivity which declines rapidly within a few days after administration.

Physicochemical Properties

Molecular Formula	C39H48N4O4
Molecular Weight	636.822830200195
Exact Mass	636.367
CAS #	149402-51-7
PubChem CID	148160
Appearance	Light brown to black solid powder
Density	1.2±0.1 g/cm3
Boiling Point	980.8±65.0 °C at 760 mmHg
Flash Point	547.0±34.3 °C
Vapour Pressure	0.0±0.3 mmHg at 25°C
Index of Refraction	1.620
LogP	8.75
Hydrogen Bond Donor Count	3
Hydrogen Bond Acceptor Count	8
Rotatable Bond Count	11
Heavy Atom Count	47
Complexity	1770
Defined Atom Stereocenter Count	2
SMILES	OC1=C2C(C)=C3C=C4C(CC)=C(C)C(C=C5C([C@H](C)OCCCCCC)=C(C)C(C=C6[C@@H](C)[C@H](CCC(=O)O)C(=C(C2=N3)C1)N6)=N5)=N4 |t:6,14,29,39|
InChi Key	PUUBADHCONCMPA-USOGPTGWSA-N
InChi Code	InChI=1S/C39H48N4O4/c1-8-10-11-12-15-47-24(7)36-22(5)30-17-29-21(4)26(13-14-35(45)46)38(42-29)27-16-34(44)37-23(6)31(43-39(27)37)18-32-25(9-2)20(3)28(40-32)19-33(36)41-30/h17-19,21,24,26,42,44H,8-16H2,1-7H3,(H,45,46)/t21-,24?,26-/m0/s1
Chemical Name	3-[(21S,22S)-11-ethyl-16-(1-hexoxyethyl)-4-hydroxy-12,17,21,26-tetramethyl-7,23,24,25-tetrazahexacyclo[18.2.1.15,8.110,13.115,18.02,6]hexacosa-1,4,6,8(26),9,11,13(25),14,16,18(24),19-undecaen-22-yl]propanoic acid
HS Tariff Code	2934.99.9001
Storage	Powder-20°C 3 years 4°C 2 years In solvent -80°C 6 months -20°C 1 month Note: Please store this product in a sealed and protected environment (e.g. under nitrogen), avoid exposure to moisture and light.
Shipping Condition	Room temperature (This product is stable at ambient temperature for a few days during ordinary shipping and time spent in Customs)

Biological Activity

ln Vitro	Fluorescence pictures of 4T1 cells cultured in a solution containing 0.49 µg/mL GO-PEG, 1 µM HPPH (free HPPH), or a combination of 1 µM HPPH and 0.49 µg/mL GO-PEG for a duration of 24 hours. GO-PEG-HPPH and HPPH cellular absorption were investigated in 4T1 murine breast cancer cells. After giving cells equivalent quantities (1 µM) of GO-PEG-HPPH and free HPPH for a whole day, the cells were examined using confocal microscopy. Compared to cells treated with free HPPH, those treated with GO-PEG-HHPH displayed more pronounced fluorescent signals. In actuality, HPPH has very little fluorescence [1].
ln Vivo	Enhancing antitumor immunity while maintaining efficient control over primary tumor growth can be achieved by treating tumors with an immune-enhancing PDT regimen followed by a tumor-controlling PDT regimen. In order to investigate this theory, a combination treatment plan was created. BALB/c mice bearing Colo26-HA tumors were given the HPPH-PDT regimen, which is known to improve antitumor immunity (0.4 μmoles/ kg HPPH) by irradiating the tumor with 665 nm light (a total dose of 48 J/cm2). The mice were given an injection of HPPH on the ninth day after they had been awake for nine days. The tumor was treated with a tumor control treatment regimen (irradiation with 665 nm light, total dose 132 J/cm2) on the tenth day following the first treatment [2].
References	[1]. Photosensitizer loaded nano-graphene for multimodality imaging guided tumor photodynamic therapy. Theranostics. 2014 Jan 15;4(3):229-39. [2]. Development of photodynamic therapy regimens that control primary tumor growth and inhibit secondary disease. Cancer Immunol Immunother. 2015 Mar;64(3):287-97.
Additional Infomation	2-(1-Hexyloxyethyl)-2-devinyl pyropheophorbide-a is under investigation in clinical trial NCT01668823 (Photodynamic Therapy in Treating Patients With Lung Cancer). HPPH is a lipophilic, second-generation, chlorin-based photosensitizer. Upon intravenous administration, HPPH selectively accumulates in the cytoplasm of cancer or pre-cancerous cells. When laser light is applied, a photodynamic reaction between HPPH and oxygen occurs, resulting in the production of cytotoxic free radicals and singlet oxygen and free radical-mediated cell death. Compared to the first-generation photosensitizer porfimer sodium, HPPH shows improved pharmacokinetic properties and causes only mild skin photosensitivity which declines rapidly within a few days after administration.

Solubility Data

Solubility (In Vitro)

DMSO : ~125 mg/mL (~196.29 mM)

Solubility (In Vivo)

Solubility in Formulation 1: ≥ 2.5 mg/mL (3.93 mM) (saturation unknown) in 10% DMSO + 40% PEG300 + 5% Tween80 + 45% Saline (add these co-solvents sequentially from left to right, and one by one), clear solution. For example, if 1 mL of working solution is to be prepared, you can add 100 μL of 25.0 mg/mL clear DMSO stock solution to 400 μL PEG300 and mix evenly; then add 50 μL Tween-80 to the above solution and mix evenly; then add 450 μL normal saline to adjust the volume to 1 mL. Preparation of saline: Dissolve 0.9 g of sodium chloride in 100 mL ddH₂ O to obtain a clear solution. Solubility in Formulation 2: ≥ 2.5 mg/mL (3.93 mM) (saturation unknown) in 10% DMSO + 90% (20% SBE-β-CD in Saline) (add these co-solvents sequentially from left to right, and one by one), suspension solution. For example, if 1 mL of working solution is to be prepared, you can add 100 μL of 25.0 mg/mL clear DMSO stock solution to 900 μL of 20% SBE-β-CD physiological saline solution and mix evenly. Preparation of 20% SBE-β-CD in Saline (4°C，1 week): Dissolve 2 g SBE-β-CD in 10 mL saline to obtain a clear solution. Solubility in Formulation 3: ≥ 2.5 mg/mL (3.93 mM) (saturation unknown) in 10% DMSO + 90% Corn Oil (add these co-solvents sequentially from left to right, and one by one), clear solution. For example, if 1 mL of working solution is to be prepared, you can add 100 μL of 25.0 mg/mL clear DMSO stock solution to 900 μL of corn oil and mix evenly.  (Please use freshly prepared in vivo formulations for optimal results.)

Preparing Stock Solutions		1 mg	5 mg	10 mg
	1 mM	1.5703 mL	7.8515 mL	15.7030 mL
	5 mM	0.3141 mL	1.5703 mL	3.1406 mL
	10 mM	0.1570 mL	0.7852 mL	1.5703 mL

*Note: Please select an appropriate solvent for the preparation of stock solution based on your experiment needs. For most products, DMSO can be used for preparing stock solutions (e.g. 5 mM, 10 mM, or 20 mM concentration); some products with high aqueous solubility may be dissolved in water directly. Solubility information is available at the above Solubility Data section. Once the stock solution is prepared, aliquot it to routine usage volumes and store at -20°C or -80°C. Avoid repeated freeze and thaw cycles.